Method for treating yarns having potential crimping property



Oct. 7, 1969 MASAO MATSUI EI'AL METHOD FOR TREATING YARNS HAVING POTENTIAL CRIMPING PROPERTY Filed April 8, 1966 ATTORNEY United States Patent 3,471,605 METHOD FOR TREATING YARNS HAVING POTENTIAL CRIMPING PROPERTY Masao Matsui and Susumu Tokura, Osaka, Japan, as-

signors to Kanegafuchi Spinning Co. Ltd., Osaka, Japan, and Snia Viscosa Societa Nazionalelndustria Applicazioni Viscosa S.p.A., Milan, Italy Filed Apr. 8,1966, Ser. No. 541,367 Claims priority, application Japan, Apr. 14, 1965, 40/22,024

Int. Cl. D02g 1/00 US. Cl. 264168 3 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a method for treating yarns having a potential crimping property to cause the development of the crimps. It is wellaknown that a composite filament consisting of at least two components of different shrinking properties eccentrically arranged and bonded together can be caused to develop its threedimensional crimps by heating, swelling or otherwise treating the same. However, the above-mentioned crimp developing treatment, particularly continuous treatment of continuous filaments, involves various difliculties, so there is still no practical method or apparatus for-such crimping treatment.

One of these difficulties is the problem of stabilizing tension at the time of treatment. That, is, it is necessary to feed yarns in substantially tensionless condition at treatment'lf the speed ratio between feeding rollers (letting-in rollers) and delivering rollers (taking-out rollers) is "maintained at a proper value corresponding to the shrinkage of the filaments, the yarn can somehow be fed in tensionless condition, but once the proper speed ratio is deviated from, even in a slight degree, such unbalanced components are built up, whereupon a failure occurs owing to either excess or want of the required amount of yarn between these rollers. The range of this proper condition is usuallylimited'to a very narrow allowance. 1

Accordingly, the present invention is intended to provide a method for stabilizing the tensionless condition.

Thus, the invention utilizes an apparatus for continuously feeding yarns into a treating bath and delivering them therefrom, characterized in that a delivering device such as rollers has its yarn nipping part placed substantially in a treating liquid or another liquid connected thereto.

The term efiective delivering speed used herein is defined as a length of a yarn in tensioned condition delivered per unit time by being nipped between two rollers or gears.

According to the invention, when the tension at the time of treatment is decreased, the effective delivering speed is increased, and, inversely, when the former is increased, the latter is decreased, so that this automatic balancing effect allows the feeding of yarn substantially in a tensionless and stabilized condition. A manner in which the invention is embodied will now be described with reference to the drawing, wherein:

3,471,605 Patented Oct. 7, 1969 FIG. 1 is a schematic view illustrating diagrammatically the process of and apparatus for practicing the present invention.

FIG. 2 is a vertical sectional view showing an example of the yarn feeding part of the present apparatus.

FIGS. 3-6 are vertical sectional views each showing a different modified form of the yarn delivering part which constitutes the principal portion of the present apparatus.

FIGS. 7 and 8 are side views showing fibers in crimped condition.

In FIG. 1, a yarn z unwound from a composite filament yarn pirn 1 is fed at a constant speed by means of feeding rollers 5 and 6 through a guide 3 and a tension regulator 4. It is then passed in tensionless condition into a treating tank or bath 9 through an air nozzle 8 actuated by the air supplied as indicated at 7.

In the treating bath there is a treating liquid 10 being heated by a heater 12. The heater 12 may be replaced by any other suitable means, such as heating the peripheral wall of the treating bath, or supplying a preheated treating liquid to the bath.

The yarn 13, which has developed its crimps, proceeds along a guide plate 11 and is delivered at a constant speed by means of delivering rollers 14 and 15 placed in the liquid.

It passes through a guide 16, a tension compensator 17 and a traversing means 18 and is wound on a reel 20 driven by a cylinder 19.

In this case, if a drier is placed between the members 16 and 18, a dry yarn is obtained. The feeding rollers 5 and 6 may be Nelson rollers. In case that the yarn is so thick as it will fall down by its own weight, the air nozzle 8 is unnecessary, and instead the feeding rollers may be mounted at a suitable place above the liquid. Further, as shown in FIG. 2, the feeding rollers may be half dipped in the treating liquid. In any case, whatever type the feeding device may be, it is sutficient only if it is so arranged that it may continuously feed yarns at a constant speed in tensionless condition. As to the deliver: ing device, it is necessary that the yarn nipping point thereof be substantially in the liquid.

The delivering device may be of the type shownin FIG. 1 consisting of a driving roller 15 and a holding roller 14, or the type shown in FIG. 3 consisting of two driving rollers x and y and a holding roller z, or the type shown in FIG. 4 having an apron-roller assembly comprising two cooperating endless belts 25 and 26 and their associated pulley belts, or the type shown in FIG. 5 comprising gears 27, 28. In any case, it is necessary that it be of the type in which yarns are nipped andheld by tworotating parts (hence Nelson rollers are not suitable) and that 'a first nip point be in the treating liquid. For example, in FIG; 3 there are two nip points at the contact points between x and z and between y and z, respectively, with a first nip point, which is the contact point between x and 2, being in the. liquid. In case that there are second, third and other nip points, it is self evident that it does not matter at all whether such points are located in or outside the liquid.

Further, as shown in FIG. 6, the delivering device (rollers 30, 31) may be placed in a second liquid bath connected to the treating liquid. In FIG. 6, a treating bath A contains water e.g., at C. and a delivering part B contains water at room temperature, with both interconnected by a connecting pipe C. However, if the two are not in hydraulically interconnected relation, the

arrangement will lose its function as the delivering device of the invention.

The reason why the present apparatus can feed yarns m tensionless condition is believed to be as follows.

A bunch of yarns consisting of many crimped filaments, when in the liquid, is dispersed and is high in expanding and contracting property, as shown in FIG. 7, but when the bunch is drawn out of the liquid, the crimps of the filaments are extended, and the filaments in the bunch are gathered together as shown in FIG. 8 owing to their own weight and that of the liquid adhered to the filaments, just as a water plant will open its flowers in water, but the flowers will wither away when taken out from water. A yarn high in expanding and contracting property has a wide range of allowance in connection with the ratio between the feeding speed and delivering speed. Moreover, when it is in contracted condition, the effective delivering speed of the delivering device is increased, while when it is in expanded or extended condition, the elfective delivering speed is decreased, with the result that the placing of the delivering device in the liquid makes it possible to impart the above-mentioned automatic balancing elfect to the apparatus. However, if the delivering device is located outside the liquid, the yarn will almost lose its expanding and contracting property so that the above-mentioned automatic balancing effect does not exist.

Needless to say, the development of crimps of com posite fibers is far better when eflected by wet process than by dry process. Moreover, when it is effected by wet process, the yarn can float in the liquid, so that it is possible to create a substantially perfect tensionless condition. If the method according to the invention is employed, the advantageous features of wet process can be fully utilized.

The method of the invention will offer superior stability with respect to composite fibers formed of polyamide series, polyester series, polyvinyl series or other known series polymers, if the ratio between the feeding speed and delivering speed is so selected as to be suited to the treating conditions such as treating agent (liquid) and treating temperature and to the contracting and crimping properties of said filaments.

EXAMPLE As a first component Nylon-6 was used having an intrinsic viscosity of 0.94 in metea-cresol, and as a second component a copolyamide of 90 parts of caprolactam and 10 parts of hexarnethylene isophthalate were used, having an intrinsic viscosity of 1.19. These components were subjected to adjoining type melt spinning with a bonding ratio of 1:1 and were then drawn 3.5 times their original lengths at room temperature to provide a bunch of 110- denier/28-filament composite filaments.

1f the filaments are treated with water at 100 C. for 15 minutes, they develop their crimps, and their length when in water, becomes about 40% of the original value; but when a tension of mg./d. is applied thereto, the bunch becomes about 80% of the original length, with the apparent shrinkage disappearing. This 40% length differential is that quantity which has connection with the above-noted expanding and contracting property.

The bunch of filaments was fed by an apparatus as shown in FIG. 1 (the length of the treating bath being 1 m.) using water at C., at 20 m./min. into the treating bath.

Where the delivering rollers were placed in the treating liquid, it was possible to operate safely (i.e., to advance the bunch in substantially tensionless condition) for more than 8 hours, during which time the delivering speed (peripheral speed of rollers) was maintained at a substantially constant value within a range of 14.8 m./min. to 13.7 m./rnin.

On the other hand, where the delivering rollers were placed outside the liquid, the operation could be effected in somewhat stabilized condition for a short period of time, only if the delivering speed was under strict control so as to be maintained in a narrow range of 14.9 m./min. to 15.0 m./min.; but it was not possible to effect a long operation of more than 1 hour.

We claim:

1. A method of crimping yarns having a potential crimping property, comprising the steps of providing a thermoplastic composite multi-filament yarn of potential crimping property having at least two components of different shrinking properties eccentrically arranged in a single filament, continuously feeding said yarn in tensionless condition and at a constant speed into a heated liquid -bath so as to cause the development of crimps in said yarn, and then continuously delivering the crimped yarn out of the liquid bath at a speed less than the feeding speed of the uncrimped yarn into said bath by nipping the yarn in a nip formed in the bath by at least two rotating rollers, thereby maintaining the crimped yarn in a loose, tensionless condition as it travels through the liquid bath.

2. A method of crimping yarns as defined in claim 1, wherein the feeding speed of the yarn into said liquid bath is approximately twenty meters per minute, and the delivery speed of said yarn out of said bath through said nip is maintained, within the range of 13.7 meters per minute to 15.0 meters per minute.

3. A method of crimping yarns as claimed in claim 1, wherein the bath is water at approximately 100 C.

References Cited UNITED STATES PATENTS 3,060,501 10/1962 Beal 6844 XR 3,066,006 11/1962 Sonnino 8l5l.2 2,294,957 9/1942 Caldwell 264168 XR 2,878,547 3/1959 McMaster 61 al. 2,943,377 7/1960 Freiberger 264-168 XR 3,038,239 6/1962 Moulds 264-171 XR FOREIGN PATENTS 565,910 11/1958 Canada.

OTHER REFERENCES German printed application 1,082,873, 6/1960.

PHILIP E. ANDERSON, Primary Examiner U.S. Cl. X.R. 

